MOTOR DRIVE CONTROL DEVICE, AND FAN MOTOR SYSTEM COMPRISING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a motor drive control device that can be expected to achieve a certain brake operation at power supply stop without requiring a high-capacity capacitor nor a mechanical relay.SOLUTION: A motor drive control device 1 comprises: a switching element Q7 that is turned on when a voltage Vin of a power supply line 31 is reduced to a predetermined value or less; a capacitor C1 that stores electric charges inputted via the switching element Q7 when the switching element Q7 is turned on; a plurality of rectification elements D1-D3 that supply a capacitor voltage Vc to each control input terminal of a plurality of lower arm side transistors Q4-Q6; and a switching circuit 6 that cuts off connection between an output of a drive circuit 4 and the control input terminals of the lower arm side transistors Q4-Q6 when the capacitor voltage Vc is equal to or more than a predetermined value. Thereby, a short brake operation immediately after power supply stop is achieved.SELECTED DRAWING: Figure 1